193 research outputs found

    Finding feasible timetables using group-based operators.

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    This paper describes the applicability of the so-called "grouping genetic algorithm" to a well-known version of the university course timetabling problem. We note that there are, in fact, various scaling up issues surrounding this sort of algorithm and, in particular, see that it behaves in quite different ways with different sized problem instances. As a by-product of these investigations, we introduce a method for measuring population diversities and distances between individuals with the grouping representation. We also look at how such an algorithm might be improved: first, through the introduction of a number of different fitness functions and, second, through the use of an additional stochastic local-search operator (making in effect a grouping memetic algorithm). In many cases, we notice that the best results are actually returned when the grouping genetic operators are removed altogether, thus highlighting many of the issues that are raised in the stud

    Vector bundles on the projective line and finite domination of chain complexes

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    Finitely dominated chain complexes over a Laurent polynomial ring in one indeterminate are characterised by vanishing of their Novikov homology. We present an algebro-geometric approach to this result, based on extension of chain complexes to sheaves on the projective line. We also discuss the K-theoretical obstruction to extension.Comment: v1: 11 page

    Young children, gender and the heterosexual matrix

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    In this paper I consider the adult focus of current mainstream gender theory. I relate this to how the concept of the heterosexual matrix originates in a social contract which excludes children from civil society. I argue that this exclusion is problematic both for theoretical reasons and from the perspective of children themselves. I start by discussing the nature of the heterosexual matrix and its foundations. I consider the implications for participation which arise from being named as a child, how that affects children’s attempts to claim participation in civil society, and how this is related to children’s naming of themselves as gendered. I then briefly consider the possibility that, because of their exclusion, children might also be considered to be exempt from the heterosexual matrix. However, I argue, there is considerable evidence that children are actively sexual beings who also work hard to claim inclusion in local practices of heterosexuality. I end by suggesting that there are three key reasons for this: that the discourses of normative sexuality provide children with a language to express sexual feelings; that self-insertion in the heterosexual matrix is a way for children to claim rights to participation; and that taking up heterosexual formations is a means whereby children can experience the power of naming themselves as part of the social world

    Tomboys and girly-girls: embodied femininities in primary schools

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    This paper is about how nine to eleven year old children, particularly girls, co-construct tomboy and girly-girl identities as oppositional positions. The paper sits within a theoretical framework in which I understand individual and collective masculinities and femininities as ways of ‘doing man/woman’ or ‘doing boy/girl’ that are constructed within local communities of masculinity and femininity practice. Empirical data come from a one-year study of tomboy identities within two London primary schools. The paper explores the contrasting identities of tomboy and girly-girl, how they are constructed by the children, and how this changes as they approach puberty. The findings suggest that the oppositional construction of these identities makes it harder for girls to take up more flexible femininities, though it is possible to switch between tomboy and girly-girl identities at different times and places

    The problem of gender categorisation: addressing dilemmas past and present in gender and education research

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    Developments in the field of gender theory as applied to education since the 1970s are briefly reviewed in order to highlight key challenges and debates around gender categorisation and identification in gender and education. We argue that conundrums of categorisation have haunted, and continue to haunt, the field of gender theory, and empirical applications (such as the case of education) in particular. We explain how we have attempted to address some of the conundrums arising in our own theoretical work, and analyse remaining challenges that we feel the field of education needs to address in order to advance theoretically. Identifying two key tensions underpinning this empirical dilemma of gender categorisation – the tension between agency and determinism in gender identification, and that between gender deconstruction and gender analysis – we seek to weave a path through some of these complex debates, and to indicate ways in which they may be addressed in future work. We argue that in order to avoid essentialism and reification of gender distinction, we need to apply a ‘three-fold’ analysis that incorporates three different elements in our categorisation of gender: spectator perspective; respondent perspective and social context

    Improving the performance of a preference-based multi-objective algorithm to optimize food treatment processes

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    This work focuses on the optimization of some high-pressure and temperature food treatments. In some cases, when dealing with real-life multi-objective optimization problems, such as the one considered here, the computational cost of evaluating the considered objective functions is usually quite high. Therefore, only a reduced number of iterations is affordable for the optimization algorithm. However, using fewer iterations can lead to inaccurate solutions far from the real Pareto optimal front. In this article, different mechanisms are analysed and compared to improve the convergence of a preference-based multi-objective optimization algorithm called the Weighting Achievement Scalarizing Function Genetic Algorithm (WASF-GA). The combination of these techniques has been applied to optimize a particular food treatment process. In particular, one of the proposed methods, based on the introduction of an advanced population, achieves important improvements in the quality indicator measures considered

    Emerging Artificial Societies Through Learning

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    The NewTies project is implementing a simulation in which societies of agents are expected to de-velop autonomously as a result of individual, population and social learning. These societies are expected to be able to solve environmental challenges by acting collectively. The challenges are in-tended to be analogous to those faced by early, simple, small-scale human societies. This report on work in progress outlines the major features of the system as it is currently conceived within the project, including the design of the agents, the environment, the mechanism for the evolution of language and the peer-to-peer infrastructure on which the simulation runs

    Teacher agency in curriculum making: agents of change and spaces for manoeuvre

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    In the wake of new forms of curricular policy in many parts of the world, teachers are increasingly required to act as agents of change. And yet, teacher agency is under-theorised and often misconstrued in the educational change literature, wherein agency and change are seen as synonymous and positive. This paper addresses the issue of teacher agency in the context of an empirical study of curriculum making in schooling. Drawing upon the existing literature, we outline an ecological view of agency as an effect. These insights frame the analysis of a set of empirical data, derived from a research project about curriculum-making in a school and further education college in Scotland. Based upon the evidence, we argue that the extent to which teachers are able to achieve agency varies from context to context based upon certain environmental conditions of possibility and constraint, and that an important factor in this lies in the beliefs, values and attributes that teachers mobilise in relation to particular situations
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